1. Field of the Invention
The present invention relates to a strap wrench, and more particularly to a strap wrench for driving tubular members.
2. Description of the Prior Art
Typical strap wrenches are developed for driving tubular members. The applicant has developed one of the typical strap wrenches and disclosed in U.S. Patent No. 6,125,723 to Huang. The strap wrench includes a pawl or a cam biased to engage with a strap that may be used for clamping and driving the tubular members. However, the cam may not be used to solidly engage with the is strap.
The present invention has arisen to mitigate and/or obviate the afore-described disadvantages of the conventional strap wrenches.
The primary objective of the present invention is to provide a strap wrench including a pawl that may be solidly forced to engage with the strap for preventing the strap from being moved relative to the pawl, and for allowing the strap to solidly engage and clamp the object to be driven or rotated.
In accordance with one aspect of the invention, there is provided a strap wrench comprising a head including a handle extended therefrom, and including a channel formed along the head and the handle, a strap slidably engaged through the channel of the head and the handle, and including a first end secured to the head, and including a middle portion having a loop formed therein for receiving an object to be driven by the strap wrench, and a pawl including a middle portion pivotally secured to the head with a pivot shaft, and including a first end having at least one tooth provided thereon for engaging with the strap and for securing the strap to the head, and including a second end having a lever extended therefrom. The tooth of the pawl is allowed to be forced to engage with the strap when the lever is forced toward the head by the loop and the object.
The head includes a chamber formed therein for receiving the pawl, and includes a partition provided between the channel and the chamber of the head, the partition includes an orifice formed therein for receiving the tooth of the pawl and for allowing the tooth of the pawl to be engaged with the strap.
A spring biasing device is further provided for biasing the tooth of the pawl to engage with the strap and includes a spring blade extended from the pawl and engaged with the head for biasing the tooth of the pawl to engage with the strap and for further solidly forcing the tooth of the pawl to engage with the strap and thus for further solidly securing the strap to the head.
The head includes a bulge extended therein, the spring blade includes a first end extended from the pawl and includes a second end engaged with the bulge for allowing the spring blade to bias the tooth of the pawl to engage with the strap.
The lever of the pawl includes a hand grip provided for rotating the lever relative to the head and for disengaging the tooth of the pawl from the strap and for allowing the strap to be freely slid relative to the head and the handle.
The head includes an opening and an aperture formed therein for slidably receiving the strap, the aperture of the head includes a width greater than that of the opening of the head, the first end of the strap includes an enlarged latch provided thereon and engaged in the opening of the head for detachably securing the latch in the opening of the head.